QUANTICO, Va. - A Marine who was shot to death at a Virginia base was described as a warm-hearted country boy from the South who grew up in the Pentecostal church and even preached a few times.

Jacob Wooley, 23, of Mississippi, was killed on Thursday by Sgt. Eusebio Lopez at the Marine Corps Base Quantico in northern Virginia, military officials said. Lopez also shot 19-year-old Lance Cpl. Sara Castromata to death before he killed himself. Castromata, of Oakley, Calif., was a warehouse clerk. He joined the corps in May 2006 and deployed in support of the wars in Iraq and Afghanistan.

The three worked at a school that tests Marines who want to become officers, but officials have not released their relationship or a motive for the shooting. Their bodies were found in the Taylor Hall barracks, where those who work at the school live. The candidates for officer live elsewhere on base.

Tiffany Wood said she met Wooley when they were teens.

"I'm just so confused. Jacob had no enemies. He was such a sweetheart," she said.

Wood said they went to the same schools in the small town of Corinth, in northeast Mississippi near the Tennessee state line.

"He was real goofy, too, like he always wanted everybody to smile. If he could lighten a situation he would," she said. "You couldn't stay mad at him. He would say something to make you laugh or make you grin."

Before joining the Marines, he had preached a few times at Central Pentecostal Church, she said. "He just had a real big heart. He would help anybody that he could."

Wooley was a field radio operator. He worked at the school, which is known for its grueling 10-week program that evaluates Marines on physical stamina, intelligence and leadership. The candidates must complete obstacle courses, hikes of up to 12 miles in full combat gear and take classes on navigation and tactics that help them in the field, according to the school's website.

Wooley had always wanted to be a Marine. He joined in February 2010.

"He loved the Marines. I have friends that have joined and they hate it. But it was his passion to help people," Wood said.

Wooley's great-aunt Jean Luker said after high school, Wooley went to Northeast Mississippi Community College and then the Marines.